Lyndon Brown authored May 26, 2021 and Jean-Baptiste Kempf committed Jun 12, 2021

under this algorithm codes are searched first, names second. (though of
course codes are skipped if length is not 2 or 3).

in short, this is partly because in cases where clashes between short
names and codes occur (which can happen, as discussed shortly), i feel
that it is best to prefer the code match, and partly because of the
disadvantages of using names as identifiers, as discussed in a moment,
that make codes perhaps more likely to be used for most languages.

please note the note in the previous commit about how this is only of
relevance to users specifying language preference for dvdnav and bluray,
with `--sub-language`, `--audio-language` and `--menu-language` options.

-- names as identifiers --

the disadvantages/problems of using names as identifiers:

 1. first, note that since 236ca7ae
    introduced the possibility, the help text of the few relevant
    options has never actually informed user...